SCOTTSDALE, Ariz. -- Right-hander Rubby De La Rosa, acquired in the offseason trade that sent Wade Miley to the Red Sox, will get the start for the D-backs in their Cactus League opener on Wednesday afternoon against the Rockies at Salt River Fields.

D-backs manager Chip Hale has been impressed with the way Cahill, who is competing for a rotation spot, has looked in bullpen and live batting practice sessions.

"We've noticed the ball coming out of his hand much better," Hale said. "It's just a matter of now seeing it translate to a game. If we see what we've seen in the bullpen he'll be one of our five, no doubt. We're excited about what we're seeing so far."

Left-hander Robbie Ray will start Friday against the A's, 1:10 p.m. MT at Salt River Fields.